Fix #824/SNOW-466: Window Creation Error related to FSAA

- Linux only: Retry window creation with lower FSAA samples if it
fails.
- All platforms: save actual FSAA level into RenderFSAASamples after
window is created.

This exapnds on the patch from SNOW-466 by Robin Cornelius.

3 files changed, 17 insertions, 0 deletions

diff --git a/linden/doc/contributions.txt b/linden/doc/contributions.txt
index 8aab5c8..6a41ddf 100644
--- a/linden/doc/contributions.txt
+++ b/linden/doc/contributions.txt
@@ -528,6 +528,7 @@ Robin Cornelius
         SNOW-108
         SNOW-196
         SNOW-422
+        SNOW-466
         SNOW-485
         VWR-2488
         VWR-9557
diff --git a/linden/indra/llwindow/llwindowsdl.cpp b/linden/indra/llwindow/llwindowsdl.cpp
index edfe33b..2f9de6b 100644
--- a/linden/indra/llwindow/llwindowsdl.cpp
+++ b/linden/indra/llwindow/llwindowsdl.cpp
@@ -632,6 +632,15 @@ BOOL LLWindowSDL::createContext(int x, int y, int width, int height, int bits, B
                         mWindow = SDL_SetVideoMode(width, height, bits, sdlflags);
                 }
 
+                while (!mWindow && mFSAASamples > 0)
+                {
+                        llwarns << "Window creating failed with " << mFSAASamples << "x FSAA."<<llendl;
+                        mFSAASamples = mFSAASamples>>1;
+                        SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, mFSAASamples ? 1 : 0);
+                        SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, mFSAASamples);
+                        mWindow = SDL_SetVideoMode(width, height, bits, sdlflags);
+                }
+
                 if (!mWindow)
                 {
                         llwarns << "createContext: window creation failure. SDL: " << SDL_GetError() << llendl;
diff --git a/linden/indra/newview/llviewerwindow.cpp b/linden/indra/newview/llviewerwindow.cpp
index 57580cf..e6b207b 100644
--- a/linden/indra/newview/llviewerwindow.cpp
+++ b/linden/indra/newview/llviewerwindow.cpp
@@ -1278,6 +1278,13 @@ LLViewerWindow::LLViewerWindow(
         LLAppViewer::instance()->forceExit(1);
         }
         
+        const U32 real_fsaa = mWindow->getFSAASamples();
+        if (real_fsaa != gSavedSettings.getU32("RenderFSAASamples"))
+        {
+                LL_WARNS("Window") << "Window created with reduced anti-aliasing samples: " << real_fsaa << "x FSAA." << LL_ENDL;
+                gSavedSettings.setU32("RenderFSAASamples", real_fsaa);
+        }
+
         // Get the real window rect the window was created with (since there are various OS-dependent reasons why
         // the size of a window or fullscreen context may have been adjusted slightly...)
         F32 ui_scale_factor = gSavedSettings.getF32("UIScaleFactor");